From the Shangri-La Diet forums:

I stumbled on SLD when I, after a sinus-infection, lost my ability to smell and therefore also taste the flavor of the food I was eating. I could only tell if the food was sweet, sour or salty. I was devastated especially after reading that it could very well be permanent. During those days I noticed how much the flavor of the food means to me but also how my appetite was affected. I just didn´t want to eat. After 3-4 days my ability to smell started to return slowly slowly to my great joy and so did my appetite.

Many people report similar experiences: loss of appetite and weight following loss of smell. Of course, you can simulate loss of smell by closing your nose with swimmer’s nose clips ($4) when eating. By what factor is that easier, cheaper, faster, and safer ithan bariatric surgery? One million?